Egg freezing is a rapidly growing fertility option for women with many different medical or personal circumstances. This treatment provides an excellent opportunity for fertility preservation in patients facing ovarian surgery for benign disease, in cancer patients (especially those undergoing chemotherapy or radiation therapy), and for choosing to postpone childbearing. Egg freezing is often undertaken by women not yet ready to become parents, as well as those concerned about diminishing ovarian reserve, those facing serious illnesses or long-term medical treatment, or their “biological clock ticking”.
Finally, this option offers clinical benefits for use in egg donation programs and egg banking, for minimization of ovarian hyperstimulation syndrome (OHSS), for oocyte accumulation in low-responder patients or young women with a strong family history of premature ovarian failure, and as importantly, for rescuing In Vitro Fertilization (IVF) cycles when there is a failure to obtain sperm for fertilization.
History of Egg Freezing
In terms of the history of egg freezing as a viable treatment alternative, the Practice Committee of the Society for Assisted Reproductive Technology and the Practice Committee of the American Society for Reproductive Medicine (ASRM) stated in 2007 that oocyte cryopreservation (egg freezing) was still an experimental procedure primarily because data on clinical outcomes were limited. In 2008, ASRM held the position that oocyte cryopreservation is experimental due to the limited number of established pregnancies and deliveries from cryopreserved oocytes. However since then, a vast number of studies have emerged in peer-reviewed journals that demonstrate that “there is adequate scientific evidence of safety and efficacy” of this treatment. As a result, oocyte cryopreservation in humans is currently a commonly practiced technique with no proven increase in birth defects as compared to fresh-oocyte IVF. In fact, at the 2011 ASRM annual meeting, during the Interactive Session/Interactive Debate – Oocyte Cryopreservation as an Alternative to Embryo Cryopreservation in the IVF patient, it was pointed out that:
“…As of 2010, the number of comparative studies of oocyte cryopreservation published in peer-reviewed journals that demonstrates “there is adequate scientific evidence of safety and efficacy” has exploded. A number of ART programs are offering oocyte cryopreservation as an alternative to embryo cryopreservation to their patients and strongly feel the “experimental” designation should be removed from the procedure.”
In 2012, ASRM removed the experimental label.
Overview of Egg Freezing
Similarly to in vitro fertilization, the process of egg freezing involves a series of steps including patient screening, injectable fertility medication therapy, transvaginal ultrasound guided egg retrieval, and subsequent freezing of the patient’s eggs. Prior to starting any treatment, women are required to undergo laboratory evaluation/testing for certain sexually transmitted diseases including syphilis, hepatitis and AIDS. Ultrasound and hormonal blood screening (FSH and Estradiol testing) is also undertaken to assess the patient’s egg quality (ovarian reserve) and thus determine the appropriate treatment protocol she would require. Finally, women who may be considering the procedure would be informed ahead of time about the process involved and the clinical outcomes that reasonably can be expected to enable them to make an informed decision and give valid consent. Counseling by a qualified mental health professional is also provided as needed.
Egg Freezing is an advanced method of assisted reproductive technology in which the woman’s eggs are matured, retrieved, and then cryopreserved (frozen) for future use. At that time, these eggs would be thawed and fertilized with the sperm, and the resultant embryos are then transferred to the woman’s uterus (embryo transfer) in hopes of achieving a pregnancy. Initially, the patient undergoes ovulation induction therapy (superovulation) with a combination of injectable fertility medications that results in the development of multiple eggs in both ovaries, and this process is monitored by sequential blood testing and ultrasound assessments. When the eggs have sufficiently matured, the transvaginal ultrasound-guided egg retrieval procedure is then performed in our office, with an anesthesiologist present to provide complete pain relief. The eggs retrieved are then cryopreserved and stored in liquid nitrogen. This is all done on-site in our embryology laboratory. The patient is discharged home soon after the procedure.
The cryopreserved eggs are thawed at a later date as per the patient’s desires. Once the eggs are thawed, they are then fertilized via Intracytoplasmic Sperm Injection (ICSI), a technique of gamete (sperm/egg) micro-manipulation, or assisted fertilization, in which individual sperm are captured in a microscopic glass pipette and meticulously injected directly into the individual eggs. The resultant fertilized eggs (early embryos) are then allowed to grow and mature in the sterile laboratory conditions in a manner similar to that of standard IVF, and they are then transferred into the woman’s uterus in order to achieve a pregnancy. A critical component of this embryo transfer is the preparation of the women’s endometrial lining with injectable and vaginal estrogen and progesterone therapy, and its synchronization to receive and support the transferred embryos. These are usually transferred at the Day 5 stage as a Blastocyst Transfer.
Success rates of Oocyte cryopreservation:
With respect to the success rate of egg freezing, advances in cryopreservation techniques, e.g. vitrification, and especially the use of ICSI, have led to significant improvements in outcomes over the years. In fact, in some laboratories, fresh embryo cycles, frozen embryo cycles, and frozen oocyte cycles have shown comparable rates of clinical pregnancies and deliveries, and other investigators have found that children conceived from cryopreserved oocytes show no increase in significant birth defects and develop normally.
In a systematic review and meta-analysis of randomized controlled trials by Cobo, et. al. from the August, 2011 volume of the journal, Fertility and Sterility, the achieved success rates demonstrated that the potential of fertilization and pregnancy from frozen oocytes derived from vitrification/warming cycles is not significantly different from that of fresh oocytes in standard IVF cycles.
In addition, age-related prognosis estimates of success rates by Dr. Daniel Shapiro of RBA in Georgia conclude that women freezing their eggs between the ages of 32 and 35 have a subsequent 40 – 50% chance of achieving a successful pregnancy, those who do so between the ages of 35 and 38 have a 35% chance, those at 39 or 40 have a 20 – 25% chance, and freezing eggs over the age of 40 is associated with a less than 10% success rate. Once again, these rates are quite similar to those expected for fresh IVF treatment, and as with most fertility therapies available, the prognosis for pregnancy from egg freezing is significantly correlated with the woman’s age.
Current status of Egg Freezing:
In 1984, the first baby conceived using an egg that was previously frozen and thawed was born. In 2009, there were over 1000 live births from oocyte cryopreservation worldwide, and 51% of ART centers surveyed in the United States offered this treatment. In 2012, over 1500 healthy babies have been born, and this number is increasing every year. Given that fertility is age-dependent, it is felt by many that freezing eggs can be interpreted as an act of preventive medicine, allowing women to avoid the potential disappointments that are associated with the lower effectiveness of fertility treatments at older ages.
In 2012, an estimated 5,000 women nationwide are making use of oocyte cryopreservation. Currently, understanding and addressing all of the risks and benefits of this technology, oocyte cryopreservation is indisputably growing in popularity. Given the concerns that many patients have over the reality of their biological clock, egg freezing empowers women with a method to help maintain their future fertility.
While currently it is unlikely that most insurance companies will provide coverage for egg freezing, each individual plan is different and patients can check with our office for costs associated with this therapy. Ultimately, some say that the treatment itself can be viewed as a powerful insurance policy to help protect a woman’s reproductive future.
To learn more, please contact us online or by phone at 732-339-9300, or please continue reading on our Frequently Asked Questions page. Please also view our blog articles on egg freezing by clicking here.